Wayne's a retired engineer (we know how dangerous THAT breed is ) and he's got a website that's basically a brain dump of things he knows about. He has a section for Awana Grand Prix (and Pinewood Derby) cars. He does a lot of analysis of different speed techniques, giving his opinion about whether a particular technique is worth it. Some of the stuff is actually pretty useful, like microscopic examination of axle polishing techniques.
One thing he weighs in on is rail riders. You can see his write-up here. http://waynesthisandthat.com/awana.htm#railriders
He is not supportive of the concept of rail riding. He writes:
When the car ran along the left side of the guide rail it was faster, validating the concept. But, when it ran against the right side it was slower. Either the rail sides are not equally smooth, there are protrusions that catch the wheel or the car was aligned with too much pressure on the right side of the rail. What this shows it that to make a rail rider work you'd need access to the track before the race to find out which side of the rail is best and then fine tune the car's alignment to that rail. Even that wouldn't help because cars are required to run on all tracks and one track may be completely different that another. Considering that at most meets the track is strictly off limits prior to the race makes the likelihood of getting a rail rider tuned to that track very small.
Yes, there have been successful rail riding cars that have won championships. But how much of that was luck or the lack of competition? Anyone building a rail rider is going to be well versed in all the other aspects of Awana Grand Prix car construction and their car is likely going to be a high performance vehicle that may very well have won even if it hadn't been aligned as a rail rider.
For myself, this technique has too many risks to advocate.
Now, one frustrating thing is that Wayne is, apparently, busy with some project, so he can't be contacted and doesn't publish his email. If he did, I'd have a lot of questions for him. Since I can't ask him directly, I'll post them here. Maybe Wayne reads Derbytalk.
* How did you build your rail riders? Did you narrow the front end on the DFW? Did you align the rears first? Did you check to make sure that the rears were staying off of the track when you ran?
* What kind of camber are you running on the rear axles and on the front DFW? How many inches of drift is your toe-in set for?
* Are your rail-riders 3-wheelers or 4-wheelers? Have you been attempting to ride the rail on the raised wheel?
* Is one side of your test track strip rougher than the other?
Ball's in your court, Wayne. Defend your anti-rail-riding thesis.